Base for electrical devices



March 18, 1941. THAL 2,235,656

BASE FOR ELECTRICAL DEVICES Filed July 12, 1940 lnvewkor': Geor That,

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Hi5 A'fkOFneg.

Patented Mar- 18, 1941 2,235,656

UNITED STATES PATENT OFFICE BASE FOR ELECTRICAL DEVICES Thai, Berlin, Germany, assignor to GeneralkElectric Company, a corporation of New Yo! Application July 12, 1940, Serial No. 345,245 In Germany July '1, 1939 2 Claims. (Cl. 17642) My invention relates to electric lamps in gengage the surrounding outer sleeve and provide a eral and more particularly to lamps which are reliable electrical contact between the inner and adapted to project only a narrow beam of light outer sleeves at all times as well as a firm mountsubstantially in one direction. Still more paring for the outer sleeve. ticularly, my invention relates to a rotating base The rotating base makes it possible to rotate 5 construction for such lamps whereby the lamp the lamp at will to the left or to the right by can be rotated in its socket after having been inapproximately 360 after the lamp has been serted therein. screwed into a socket. The production and use In the case of electric lamps which are adapted of the base are simple because it is only necesill to radiate light mainly in one direction, such as sary to slide the outer base shell over the end of those used particularly for signaling purposes, the inner sleeve either before or after the latter headlight purposes and air-raid protection, it is is cemented to the lamp bulb, and to roll the edge frequently desirable to change the direction of of the outer base shell into an annular groove in light radiation by rotating the lamp in its socket. the inner sleeve so that the interengaging an For this purpose, the lamp may be provided with nular rib and groove will permit rotation of the 15 a rotating base construction such as that debase but not an axial displacement or removal scribed and claimed in Patent No. 2,165,987, of the same. Sobczak et al., issued July 11, 1939 and comprising Further objects and advantages of my invenan inner threadless sleeve cemented to the bulb tion will appear from the following description neck, and an outer threaded or bayonet-type base of a species thereof and from the accompanying 20 shell rotatably mounted on said inner sleeve by drawing in which: means of an inwardly-extending annular rib spun Fig. 1 is a longitudinal sectional view, partly into a corresponding annular groove in the inner in elevation, of an electric incandescent lamp for sleeve. Such a construction does not provide of air-raid protection purposesprovided with a base itself a. very reliable electrical connection between comprising my invention; and Fig. 2 is a cross- 25 the outer base shell and the inner sleeve, so that section on the line 2-4 of Fig. 1.

the continuity of lamp operation is not assured at Referring to the drawing, the lamp there shown all times. In addition, such a construction does comprises a pear-shaped glass bulb I containing not provide of itself a. very ilrm mounting for a stem tube 2, a supporting rod or arbor 3, and a iii) the outer base shell, so that the latter is apt to filament 1, preferably a coiled tungsten wire,

wabble on the inner sleeve. As a result, the lamp supported by a plurality of support wires 4 exitself is not supported very firmly in the lamp. tending from said arbor and arranged in the socket. l form of a star. The opposite ends of the filament One object of my invention is to provide an I are connected to a pair of leading-in or curelectric lamp with a rotating base simple in conrent-supply wires 5, 6. The bulb I is evacuated 35 struction and effective in operation which will through an exhaust tube 8 which, after evacuainsure, even during the rotational adjustment, a tion of the bulb, is tipped or closed off as shown reliable electrical contact between the various in the drawing. The lamp bulb I is provided parts of the base and between the base and the with an opaque light-absorbing coating III over socket so as to maintain the flow of current to its entire outer surface with the exception of a 40 the lamp filament at all times. small laterally arranged light outlet window 9 Another object of my invention is to provide which may be circular or of any other desired an electric lamp with a, rotating base structure shape. If desired, the opaque coating Hl may the rotating member of which is firmly mounted be placed on the inner surface of the lamp bulb on the lamp so as to provide a ilrm support for instead of on the outer surface. The portion of 45 the lamp in its socket. the lamp bulb in which the window 9 is located The improved rotating base according to the is made substantially flat, and the window 9 is invention comprises an. inner sleeve cemented made somewhat smaller than the flattened bulb to the lamp bulb neck and enclosed by an outer portion, as shown, so that the opaque coating It so contact sleeve or shell which is locked with realso covers the edge I] of the said flattened porspect to said inner sleeve against axial displace tion of the bulb wall. Because of the opaque ment relative thereto and which is limited in its bulb coating Ill formed with the small window 9 rotation by suitable stop means. According to therein, the light of the lamp can be emitted my invention, the inner sleeve is provided with only over a very narrowly Hunted space angle.

outwardly projecting spring elements which en- Attached to the neck I! of the bulb is a rotatable base according to the invention comprising an inner threadless metal sleeve l3 cemented or otherwise secured to the bulb neck, and a conventional screw-threaded lamp base proper rotatably mounted on the inner sleeve 13 and comprising a threaded shell M, an insulating body l5, and a bottom contact eyelet i8. The rim or edge of the shell H is formed with an. annular rib H which fits into a corresponding annular groove IS in the inner sleeve I3 to thereby pro vide the rotatable mounting of the base on the inner sleeve. The said annular rib i! may be conveniently produced by spinning or rolling the metal of the threaded shell [4 into the annular groove l8 in the inner sleeve. By reason of the interfitting annular rib l7 and groove E8, the base proper can be rotated about the longitudinal axis of the inner sleeve i3 but is locked against axial displacement relative thereto.

To limit the rotational movement between the base proper and the inner sleeve 13, suitable stop means are provided comprising a lug 20 extending longitudinally from the edge IQ of the base shell l4 and a co-operating stop pin or projection 2| formed on the free or uncovered edge portion of the inner sleeve l3 and extending radially outward therefrom. Thus, after a certain amount of rotation of the base proper relative to the inner sleeve i3, the stop lug 20 will strike against the pin 2| to thereby prevent further rotation. The arcuate extent or width of the lug 20 and of the stop pin 2i is preferably made relatively small so as to permit relative rotation between the base proper and the inner sleeve i3 approximating 360. The stop pin 2! conveniently serves as the soldering point for one of the leading-in wires 5, the other leading-in wire 6 being soldered to the bottom contact eyelet E6 of the base proper.

In order to obtain, in each rotative position of the base proper with respect to the inner sleeve 13 and during actual rotation therebetween, a reliable electrical connection between the base shell I 3 and the inner sleeve I3, as well as a support which is secured against mechanical vibration, the inner sleeve 53, at a point longitudinally spaced an appreciable distance from the internisting annular rib H and groove i8, is provided with a plurality of elastic or spring elements '22 preferably punched out of the sleeve at equally spaced points around the circumference thereof. The said spring elements 22 are bent slightly outward so as to press against the threads on the threaded base shell H. The outward pressure of the spring elements 22 against the inner side of the base shell thus insures the maintenance'of an electrical contact between the base shell i4 and the inner sleeve I3 at all times, as well as providing a firm support for the base proper on the inner sleeve l3 and consequently a firm support for the lamp in its socket.

While I have shown and described the inventlon as applied to electric incandescent lamps, it is obvious that it may be applied equally well to electric discharge lamps and discharge tubes.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A base for electric lamps or similar devices comprising an inner metal sleeve for attachment to the neck of the lamp bulb, and an outer shell shaped to engage a socket, said shell being rotatabiy mounted on and surrounding said inner sleeve and being locked against axial displacement relative thereto, said inner sleeve being provided with a plurality of outwardly projecting spring elements punched out of the metal of said inner sleeve and engaging the inner side of said shell.

2. A base for electric lamps or similar devices comprising an inner sleeve for attachment to the neck of the lamp bulb and having an annular groove, and an outer shell surrounding said inner sleeve and formed with an annular rib extending into said annular groove to thereby permit relative rotation between said shell and said inner sleeve while preventing axial displacement therebetween, said inner sleeve being provided with at least three outwardly projecting spring elements located at a point longitudinally spaced an appreciable distance from said interfitting annular rib and groove, said spring elements being arranged at approximately equally spaced points around the circumference of said inner sleeve and 4g resiliently engaging the inner side of said shell. GEORG TEAL.

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